﻿#define _CRT_SECURE_NO_WARNINGS 1

#include <stdio.h>

int main()
{
    int arr[] = { 1,2,3,4,5,6,7,8,9,10 };
    int left = 0;
    int right = sizeof(arr) / sizeof(arr[0]) - 1;
    int key = 7;
    int mid = 0;

    while (left <= right)
    {
        mid = (left + right) /2;

        if(arr[mid]>key)
        {
            right = mid - 1;
        }
        else if (arr[mid] < key)
        {
            left = mid + 1;
        }
        else
        {
            break;
        }

        if (left <= right)
            printf("下标是%d\n", mid);
        else
            printf("找不到");
    }
    return 0;
}